removing secondary butterflies

[powrd12a]

Hello all! have a ? just put on my full system (street-mega)from brocks,
bmc race filter and power commander trying to get every bit of horse power that i can before i go to the tuner.has anyone removed the sec.butterflies i have an 04 gsxr-1000 and removed them before i got it tuned, after they tuned it had great throttle responce and on the highway when cruising normal then going to wide open throttle felt great........

 

[Evil_keeps_me_young]

most will say don't do it but...i did and i love it since when does anyone need two sets of butterflies? what practical purpose does it have except to restrict when your wrist says GO!!!

 

[Mythos]

I'd be curious to know why most people say to leave them in. I can say that pulling the flies on a G2 ZX-14 makes only a very slight improvement up to ~3K rpm. <<Not worth voiding your warrenty in the first year IMO.

Mythos

 

[Big Red]

Having two sets of butterfly valves gives greater tuning flexability if you can find a knowledgeable tuner to set them up for your riding style.Unless you are dragracing it would be better to leave them alone

 

[vmaxbaby]

My tuner removed mine, I didn't get much of a choice, he is all about performance and anything that blocks air is a bad thing. I think it depends on who you talk to, for all out performance you don't need them or want them. On the street would you truly see it or feel it... don't know but I am all about the sum of all mods. Which means a little here a little there and next thing you know you have made a big difference. Case in point my mustang I added some bolt on's here and there removed factory tunes, exhaust, all the things we do to our bikes now I am 606 RWHP and I can tell you the car is a beast and only getting faster as I get more money Shelby 500 : Home Page

 

[Mythos]

^^^I'm reading that as, 'secondaries out = max power but only a little more than flies in. Sounds like my 14.'

I am not familiar with the behavior of the secondaries on the busa. Do they open at ~3K like the G2 ZX-14 or do they open slower?

A couple more questions: Would having flies out at an engine speed where the bike is mapped for flies in cause damage because the bike is running lean? Is there enough fuel for optimum power with the stock mapping to go with the extra air from fies out?

Mythos

 

[turbogpz]

No you guys have it backwards,
First....the upper part of the throttle body is larger than the final throat diameter. This larger area WITH the throttle blades does not impede airflow enough to make a difference...give some credit to Suzuki and there laminar flow engineers.

Dragracing...no wheelie bar, leave them in. The bike is smoother to launch and reduces wheelies.

anywhere else... take them out, the lowend hit is vastly changed. Much better wheelies!

 

[powrd12a]

Thanx for the input.i agree a little here and a little there will equal to more, i do both kinds of riding we go to track (englishtown) drag on friday nights have fun and talk a lot of sh*t .then on the week ends we go on 3 hour rides....im going to remove them and have it custom maped let you know how it turned out.
thanx again for the input.

 

[dean.v]

No you guys have it backwards,
First....the upper part of the throttle body is larger than the final throat diameter. This larger area WITH the throttle blades does not impede airflow enough to make a difference...give some credit to Suzuki and there laminar flow engineers.

Dragracing...no wheelie bar, leave them in. The bike is smoother to launch and reduces wheelies.

anywhere else... take them out, the lowend hit is vastly changed. Much better wheelies!

so if you only ride on the road and want the most you can get take the 2ndry butterflies out and give it a good filter/exhaust & tune

 

[nitezpeed]

Sorry guys but wat is Secondary Butterflies valve?

 

[Dozerdriver]

There are butterflies in the throttle body... two sets. they open and close to block the air passageway. One is throttle controlled and the other is electrically contolled. Not sure why the second one is in there but it is...

 

[nitezpeed]

Orh i see. Thanks..

 

[Busacure]

^^^I'm reading that as, 'secondaries out = max power but only a little more than flies in. Sounds like my 14.'

I am not familiar with the behavior of the secondaries on the busa. Do they open at ~3K like the G2 ZX-14 or do they open slower?

A couple more questions: Would having flies out at an engine speed where the bike is mapped for flies in cause damage because the bike is running lean? Is there enough fuel for optimum power with the stock mapping to go with the extra air from fies out?

Mythos

I do believe that the busa uses an "air pressure" type a/f calculation that doesn't compensate for modifications that effect it's predefined "hello world" mappings. It's map "assumes" within the parameters it was originally given.

 

[djsin]

do gen 1's and gen 2's have them?

 

[djsin]

i gues knowone is going to answer my question?

 

[Got-Busa?]

do gen 1's and gen 2's have them?

Only the Gen-II has secondary butterflies...

 

[2busa]

My tuner removed mine, I didn't get much of a choice, he is all about performance and anything that blocks air is a bad thing.

I like that tuner you have. Guy makes sense. Do not drop your bike off or else. He does not mess around.

Dragracing...no wheelie bar, leave them in. The bike is smoother to launch and reduces wheelies.

anywhere else... take them out, the lowend hit is vastly changed. Much better wheelies!

For d/racing, you pull them out, you better know how to ride. The engineers know you can't, so that is why they put them in.


<< Since everyone seems to have an opinion, come closer and smell mine. Smells like? Like the throttle is more linear with both working together. The one fly will slow the air just a touch and this is enough of an effect that if you ever owned a CV type carb, they would work perfect if you left them alone as designed.

But you set pods on instead of an air cleaner box with all that slow linear flow, it literally takes a cover shield over the pods to slow the air back down so the fuel could catch up. Yeah, no matter how you fed the fuel, it would just richen up you needed to slow the air speed because the carb just needed a redesign you messing with it. That was/is why the bad reputation/frustration, even today the chopper crowd keep experiencing there mods the hard way.

FI is a different animal. They run open loop and are sensitive to air. So if you remove the flies, you will add more air quicker into the cylinder. The faster your power is handed to you, the easier the wheelie.

Is there a slight lean condition? Yes. At a certain condition; like a fast open throttle. Will it hurt the bike? No. Because it is so momentarily that the secondary is on the open anyway and will feel that stumble away as if was there.

Ordinary street riding, will it hurt the bike? No, the rpm's are slow enough that you feel it rides the same. Just a little peppier on the bottom.